Method of and apparatus for engine-braking.



Gl B. REED.

METHOD OF AND APPARATUS FOR ENGINE BFAKlNGI APPLICATION HLED AuG. 24.1917.

l ,300,0 1 6 Y Patented Apr. 8, 191,9.|

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GEORGE n. REED, VonYPHin-Anntrim-A, rEarias.YLvA'iI'QeL.=

^ Specification of'Letters lPatent.

Y METHOD or AimAPrAnATUsjroa ENGINE-RAKING.

Application tiled August 24, LSerial N o. i

the following is a specification.`-

My invention relates to a `method of andmeans for-braking an engine,andv thereby braking apparatus drivenby it, as for example, anautomobile orother vehicle, hoist ing or elevator apparatus, etc.

My invention resides in braking means "of the character Vreferredtolwhereb'y' elastic fluid, such as steam, air.V or gas, is introducedinto and confinedin the cylinder fofthe en-A gine to there oppose the,piston andresist its movement, the fluid being compressed by the pistonand allowed toescapea at suitable time and rate, ask throughfthe; valvemechanism of the, engine. f j

More particularly my invention resides in such method and vapliaratusforbraking an engine of the uni-.flow type; j y

My invention resides also inmechanism for suitably graduatingthe brakingeffect and in suitable mechanism for' controlling and changing'the pathvof l'owof the elastic Huid.

ForA anillustration of one example of my invention, reference istobehadgto the aocompanying drawing, in Whichzf y l I Figure 1 is asideelevational view', partly in section, `of the principal parts' of a,uniiiow engine equipped for braking. y Fig. 2 is a fragmentarysectional view, on enlargedy scale, through the""slide valveniechanismand associated parts.' y y Fig 3 is a cross'sectional view,Vsomepafrts in plan, taken on the' line 3 3 of Fig. 2."y

Fig. 4i is a fragmentary sectional `vieu7 taken on theline 4.-'4' ofFig. 2.

Fig. 5 `is a fragmentary sectional` view, some parts in elevation,ofeontrolling valve mechanism.

f Fig. 6 is a fragmentary sectional .view 'indicating structure of thethrottle valve.`

Referring to the'drawings, S is the engine shaft, rrotated by :theengine and in turn driving the load, Which may be al vehicle orautomobile.l Secured upon the shaft Sl is' thecrank a having thereonthecrankV pin yb upon vvvhichfis journaled one end ofthe connectingrodcy vvhsfe' other endis pivoted ratentu Apns, 191e. l

tudinallyzin the cross `head guides f, f. To

"the cross head e isseciired the piston rod ylinder Gand 'g extendingAlinto the engine carrying at its 'end the piston P.

-Upo`n the lshaftS are the usuall eccentrics *the interior Aof a, steamchest Ia'where it is -securedt the slide Mvalvefframe fml having atVitsother end the guide rods 01,01. In .openings "0",".0 in the-valveframe are,K disposed the loosely fitting valve members `19,12 hav- I ingtlieports g, g'adapted tofcommunicate with .the 'cylinder lports gr incommunication-through the passages r', r with the portss, s opening intothe interior ofthe fcylinderC at opposite ends thereof.`

Disposed vabove the slide valve members 20, p -is the plate'y tpivoted-atu, a to y'the sleeve membero ,shaving av longitudinal bearingupon the eccentric 'fw upontheshaft w which Aextends to fthe exterior ofthe valve, or steam chest/l5r and is attached to the ro *tayfA memberofthe throttle valve T, Figs.

` 1 andf6, 'actuatedY by the operating lever y. lThepla-telf has portsor openings" 251, tf1', with which ,and the ports/"13Wv the ports 'g5.g/` are adapted 'to communicate.

v Communicating With the interior fof'jt'he la), 7L', as cfa-*Stevensonlink motion Lyon any steamer valve vchest 7c is the pipeQ-aconi-VVmunicating` at its other" end, Figs".V 1,1 and,

with' the4 interior: of the; 'valve' casing a?, with;

- the interiorn of which tliepipe 221,' controlledby throttle*l valve T,com'I'ninicatesi throughV -the'portf c1. Movablelongitudinally"'ivitliinY .l y

the valve casing t1 isthe valve'membfdl actuatedj by the'lrod 'e1 whichis 'in ated'by the handleverf f1.1" l' Communicating Ai'vlthkv the?interiorv of the cylinder Cfatsubstantially mid-Way of fits i length isthe exhaust Aport` E to which fcon-v 'n nects the pipeg.1 which at itsother end conr niunicates with'the interior :ofthe valvecas- 2 f ingel.von .that side of theport o1 'opposite toY the pipe a'.Adjacent;thefcasingfathe pipes e andjg? are' connected througlnthepipes/'1.l f

and 1 with the pipe jl, a valve k1 determining which of thepipes or g1shall communicate ivit'h the pipe' jl. nThe valve lvlis actu-` atedthrough 4any suitable connections, as the being iii'positionjt'o preventcomn'iunication y'. between thel `pipe e and the exhaust pipe y".

Accordingly steam YwillY pass, in the position illustra-ted, vto theleft. end of; the cylinder C tlii'oughfthe left-hand valve member pwhose port gis iirljegisterwith the leltjhand port fr.--'I`liis`Y causestlie`l piston P to be orcedtoiivardtheright,` VFigzd, to rotat-the shaftS lwhich drivesthe,vehicle or other loadand Vsiinjultaneous]yk ac-tuates`the valve'l rod in sui-table phase relation and'tlirough suitable Ilstroke :as determined bythe link motion L,

cylinder C Which-it will be understood, is 'merely iir- `difcateddiagranfimatically and may be of any `well lineair-,types The-piston Ppasses over tlieport Efcommuii-ieating with the ipip'e gl l andvvlienreaching theA opposite en d ofthe uncovers that port,- With. the resultthatthe steam which hasl driven the pis'- vtonj .P yforward exhaustsintothe pipe g* past Athe valve M tothe exhaust. pipe j?. 'When Y Athepiston P reach-es theright hand end of the eylinderthe right' handvalvemember p lac liriits.steam into the right hand,V port i" VV ivhictithencauses steam te enter theright liagndeend of tliecyliiider C toforce the pis- ItonPbaeliivai'dly in opposite direction to furtherrotate the vshaft S in Well known manner,y and when reach-ing theposition illustrated the steainis exhausted, again l .through the vpipegli, Vvalve k1 and exhaust ln generalthe foregoing description is thatyof .the operation'of a uni-flow engine.

.Thislgeycleof operations is repeated, causing .thecontinuousrotation"of the shaft VS, for *examplek in the direction indicated by the arrow.Y

:Assuming thattlie engine drives an automobile-or other vehicleythroughsuitablelcon- .nections from the shaft S to the Wheels oi' thevehicle,the Y Vleverjfl,"lilig.. 1,7is shifted toward the right,

, pper` end .of the operating thereby moving the valve member dlftowardYthe right in the .casing 0,1 to close communication; between the portc1' and the pipe .e and to open y communication between the port ct andthe pipe gl and simultaneously shifting the valve k1 to closecommunication betweenpipes g1 and jl and to open communicationvand intothe pipe g1, formerly an exhaust pipe, into the cylinder C through theport E to one side of the piston P. The presence of the fluid in thecylinder C on that side of the piston P which in normal operation of theengine would be the exhaust side, opposes the movement of the piston Pand so causes exertion upon the shaft S of resistance to the forceexerted upon the shaft S by the moving vehicle, thereby exerting aretarding or braking effect upon the vehicle. As the pist0n P movesfarther and farther toward one end of the cylinder, it compressesthesteam lately admitted through the port E, and this steam eventuallyescapes through the eylin. der port s, passage r and port i, through theslide valve into the steam chest lo and out through the pipe e, thencepast thevalve L1 to the exhaust pipe jl. By the time the piston P` hasso operated in compressing the steam and has moved to one end of thecylinder, the steam is admitted from pipe g1 through port E totheopposite side ot the piston and opposes it in its return stroke, andthesteam isf again compressed and eventually allowed to escape throughthe-now properly positioned slide valve p into the chest o and throughthe pipe e into the exhaust pipe j), this action being cyclicallyrepeated, causing progressive braking or retardation of the engine andof the vehicle driven thereby Without reversing the engine.

The steam from the cylinder C in the braking operation tends to4 liftthe valve members p, p and to escape into chest la. The lifting of thevalve members 2J, 2J is, however, limited and controlled by the plate .tactuated by --the valve lever y., As the throttle valve T is openedWider and wider in the brakingoperation, admitting-more and more steaminto thecylinder C and causing greater and greaterpressures on the underside of the valve members p, p, they are held to the valve seat 01 moreand more closely by lthe plate t, which descends as valve T opens, Vthuscorrespondingly restricting the egress of the braking steainfrom thecylinder C and interposing greater and greater resistance to itsescapeinto chest 7c.

In other words, when a small amount ot .steam isadmitted into thecylinder through the pipe g1 `due to slight opening of the throttlevalve .'l, -it is compressed by the piston P, which lsoonshuts'ol thesteam `supply by covering-the cylinder Yport E to which the pipe g1connects, and this compressed steam escapes through the slide valvemechanism into the chest as previouslv passage g.

described, with comparative -freedom,= be-y cause of the freedomfof thelvalve :members p, p Ato liftf (But as thebrakingef'fect isincreased byfurther openingof. the throttle valve T', the valve lmembers 29,121a're'held more and more closely toithefvalve seatol,

and so reducing ,the freedomfoff escapeiofy braking steam fromhthe.cylinder Cyduring the period before -freeexhaust.through theAccordingly graduated braking eli'ectis procured?,lx

Variations' in the stroke of theslide valves 0, p or variations of thepoint y.of cut-ofjas determined by the link motion Livillihave littleeffectu'pon uthe braking action, sincethe amount of braking steam tobeexhausted from the cylinder Crwill `'never be'igreat at high speech.and at low-speed` there'will be` ample timefor exhaust of such steameveny 'when the period 'of communication; between a. cylinder port andthe valve chestfc' is short. And the ,braking action .is available alsoIvwhen the engine isrunning in opposite di- `rection to thathereinbeforeindicatedysruch reverse movement?V of..the engine vkbeing laccomplished.in wellknownnianner byl shift- =inder at substantially the endoftheforward stroke of the piston Whichin returnin .compresses the nowentrapped. steam lWhic 1v may reach a pressure higherthan the-pressureof thesource, Yand a repetition of the A action in 1 the successive`strokes Willat most bring the engine to rest and' Willineverf causeits-op eration' inreverse direction. `Olnthe 'ot'her" hand, however,when freversmg.- an.fengme,v

the elastic luidisadmiitted in such 'Way as to tend to drive'the enginein reverse direction", and the elastic; fluid opposing .the returnstroke ofvthe'piston-never exceeds the pressure ofthe source, and as the`operation continues, Willv `actually reverse the di rectionl ofmovement of the engine or motor.`

While the foregoing description *relates the same principleis`applicablefto thefcommon type of engine in which the valyelmechaf y nismis such that steam is bothadmitted and" exhausted through portssubstantially the ends of the cylinder.- f n And while I havehereinbefore indicated the application of the braking lmethod andapparatus to motor vehicles, it Will Vbe understood to be ofgeneralapplication, includ# mg the braking of engines drivingmine ork otherhoistsll elevators, etc; What I claim is:

'1, The method of braking a. reciprocating by "the control 'describedstroke, 3. 4The method oilbi'aking a reversible re-k ycipro'catlngrsteam engine 'without shiftingk piston. i

V mdjvofthe return stroke of thepi`ston..:c,. more particularly. to a.motor or' engine ofv the @uni-owtype, it. is to be understood that,engine While continuingto. rfunl :impredetermined-direction-:Whichconsists niadmltting elasticnfluid from aL source .thereof to' l fluid;by compressing the entrappediluidby the/return stroke Lof said piston,and releas- 'fing'sa'id compressed fluid;

.22.@The 'methodofbraking a engine Whileyits valvegear isset/1n posi-*i' tion for "continued running. in Ynormalv direction, which consistsind admitting V elastic fluid from a source .thereof 'to the .cylinderatsubstant-ially thefendxof eachlofthe fo1=- ,Ward strokes ofthe piston,entrapping Vand isolating the fluid fromsaidsource and compressing thesame l by the return strokes `of .1' saidr vpiston, and Areleasing thecompressed flu-id at y substantiallyy the end'v of f eachA return lthecylinder at substantiallyfthe'zend, ofthe forward stroke ,of the.pisto'rn'isolating the s' .admitted fluid fromsaid source duringreY Yturn stroke Ao'fsaid piston, convertingkinetic' f Y energy oilthevsystel'n intopressurefsaid its reversing valve gear, which consistsin" v vadmittang steam from 5a source thereQfLto.

' the cylinder; througlif Ithe lnormal ekhaust portal; substantiallytheend of theforward stroke :of the pistoneabsorbing kinetic'enf. ergy ofthe system by compressing the steam While `entrapped and.v isolatedfrom? said source in the cylinderi by'fthe'. return stroke 'oftheepiston, :and`7111eleasing the compressed steam through thenormalffi-nlet port at substantially the end of the return strokcfof'thel 4. The 'methoil' of .braking .a `eny gine While.continuingto run in'predetei`- mined* directiomwhich consists in. admitting elasticfluidtothe cylinder at substantially the end of the-forward strokeofthepiston through the normal exhaust lport substanf f tially at' thecenter'of; the-cylinder,absorb Y ing ki-neticenergy or the system` by@come pressing said' fluid While, entrapped in-Q'the cylinderl bythereturn, stroke ofthe-piston,

and,y releasing Athe compressedfluid through ythexnornial inlet. portiat substantially 'the The `colfnbination#jwith a unifflow .c en- :ginecomprising :a cy-lin der,"` valve mechanism i controlling.`vcomniunication rWithfV opposite ends` fot the cylinder, said cylinderhaving a central exhaust port,` and :means for.. con` 4 c fL nectingsaid valvemechanismto exhaustaand I for connecting ws'aid exhaustA portIWith "a source Vof fluid, wherebyluid' admitted Y .th-rough saidvvexhaust `-port into said cylinder' on opposite Asides of ythepistoniscompressed?` thereby -to 'brailfef'the y a engine .and

mechanism.I f

thereafter .exh'austed :thro-ugh f said vfvalve Y' adV`Aloaizifceoffered by said valve mechanism to escape of said fluidfromsaid cylinder with increase in lthe quantity of fluid admitted into saidcylinder .through said exhaust poi-tl .l The combination with aY.uni-floxven- Y 115 gine comprising a cylinder, valve mechanismrcontrolling communication with opposite -ends of the cylinder, saidcylinder hav- 'ring lacentral exhaust port, a vvalve for ad-4mittiiigftuid through said exhaust port vinto '-20 saidcylinderforopposing-movement of the pistoia-means allowing escape of said fluid.through said valve mechanism after compression by said piston, meanscontrolling the resistance offered by said valve mecha- .25 nismtoescape ofvfilui'd from said cylinder, and means for'contro'lling saidlast named iiaeans"and said valvein unison.

Thev combination With a uni-flow engine comprising a cylinder, valvemecha- Y nisni controlling communication with opposite endsof thecylinder, said cylinder hava central exhaust port, of a second valve lI'n'echa'nism' for reversing direction of .flow -Yoflui-d to and' fromsaid cylinderthrough said;y exhaust port and said first named valve'mechanismyl j 9. The combination with a uni-flow en- ,fgine comprisinga cylinder, valve mecha- 'nism controlling communication with oppo-4ositeends ofthe cylinder, said cylinder having Ya' central exhaustport, of a second valve niechanismfor 'reversing direction of iiowVoffliiid to and from said cylinder through said exh'afi'ist Iport and'said first named valve 5113 fniechanisim and a' throttle valvelintervening-' between' said second valve mechanism and aso'u'rce offluid.

-" 1 '10.-The combination With `a imi-HOW engine-'comprising acylinder;` valve mecha- 350 Vnis'mcontrolling communication withopposite eirds 'of the cylinder, said 'cylinderhav- 'fing acentralexhafustfport, of asecond valve yi'nechanis-m for reversing direction"of flow of fluid to `and from said cylinder through said exhaust 4portand said lirst named valve `1 mechanism, a throttle-valve interveningbeftwee'n said second valve mechanism and a source of fluid, and meansactuated in unison with sai-d throttle valve for increasing the'resistance to escape of'iluid from said cylinder:c -lirou-gh said firstnamed valve mecha- .nism 'as the opening of said throttle valveincreased. Y'

ll. YThe combination with a uni-flow en- 1 6 5 .gine com'p risingja,cylinder, valvev mecha- Vported' member from the seats of said por-tedvalve members.

l2. The combination with a uni-liow cngine comprising a cylinder, valvemechanism controlling communication with opposite ends of the cylinder,said cylinder having a central exhaust port, said valve mechanismcomprising a reciprocating trame. ported valve members disposed looselyin said .traine and adapted to lift 'from their seats,

a ported member above said valve members, of a lsecond valve mechanismfor reversing the direction of fluid fioiv to and from said cylinderthrough said exhaust port and said first named valve mechanism', meansfor varying the distance of said ported member from the seats of saidvalve members, a throttle valve intervening between the source of fluidand said second valve mechanism,

'and means vfor actuating said throttle valve 'and said lastnamedmeansin unison for decreasing the distance of said ported member from thevalve seats as the opening of said throttle valve increases.

13. The combination with an engine coinprising a cylinder-and a pistonreciprocating therein, of' means for braking the engine coiiipiisiiig asource oiE fluid, valve mechanism for admitting fluid into the cylinderat substantially theend of the forward stroke of the piston and forisolating the sameV from said source and entrapping vsaid liuid Withinsaid cylinder during the returnstroke of the piston` whereby said liuidis compressed, said valve mechanism comprising structure allowing escapeof the com- Y pressed fluid.

V14. The combination with an engine coniprising a cylinder and a pistonreciprocating therein, of valve mechanism for controlling normaloperation of s aid engine, means cooperating ivith said valve mechanismto reverse said engine, and means for braking :said engine Withoutoperation ot said Areversing means comprising valve structurecooperating with said valve mechanism for admitting fluid from a sourcethereof into said cylinder at substantially the end of' the forwardstroke of the piston and for isolating the same from said source andentrapping and compressing the fluid during the return stroke of thepiston. whereby said fluid is compressed. said valve mechanisl'nallowing escape ofthecompressed fluid at 'substantially the' end of thereturn stroke the end of the forward stroke of the piston through thenormal exhaust port substantially at the center of the cylinder,isolating and entrapping said Huid in the cylinder and compressing thesame during the return Copies of this patent may be obtained for Stroke.of said' piston to absorb" kinetieenergy from ythe system, partiallyreleasing the con1- pressed fluid during the return stroke of saidrpiston, and releasingtlie lcompressed fluid through the normal inletport at sul)-y stantially the end of the return stroke of the l Ypiston.

rln testimony yyhereof haye hereunto af fixed my signature this 3rd dayof Aug., 1917. y Y

VGEORGE B, B15113311` Washington, D. C f

ve cents each, byiiaddrenssing che loxnmsmioner of 1atents`,' i

